What's new

How would you make a circuit "self-destruct" safely?

Joined
Oct 22, 2021
Messages
38
Likes
17
Location
Canada
I need to figure this out for a non-console related project, I thought I'd try asking this here.

In essence, I need to make a circuit physically destroy itself on command, preferably only a cheap component so that it could be quickly reset by replacing it (the circuit will be on a breadboard). How could I do this reliably, with minimal risk of damaging the rest of the circuit? An rpi Pico will be connected to this thing, potentially to trigger the self-destruct among other things, so keep that in mind.

Bonus points if it breaks with a bit of spectacle (a loud pop, a flash of light, dreaded magic smoke, etc...), but I'm open to anything.
 

Stitches

2 and a Half Dollarydoos
Staff member
.
.
Joined
Feb 5, 2017
Messages
4,238
Likes
3,307
Location
Banana Bender Land, Australia
Portables
6
If you end up wanting a theatrical way to demonstrate the circuit's destruction, then in conjunction with the crowbar circuit you could use an electrolytic capacitor that is wired in with the incorrect polarity. When voltage is fed into an electrolytic cap through the wrong leg, they fail within seconds and will either open the circuit, short, rupture along the top score lines with a jet of smoke, or detonate with a loud pop and cloud of smoke (usually only the cheap caps with shallow scoring and no vents will detonate like this). Overvolting the capacitor in addition to inverting the polarity would increase your chances of a detonation, and feeding AC to a DC capacitor will almost always trigger a rapid detonation. This would obviously require safety consideration for the voltage, toxic smoke, and potentially eye damaging shrapnel, as well as using the smallest electrolytic cap that you can reliably detonate to minimise all associated risks.

See here for a practical demonstration

There's also the slightly safer option of overvolting a 3v halogen light bulb, which can make it pop if the voltage is high enough. No toxic smoke to worry about, but it will throw some little glass shards around.
 
Last edited:
Joined
Nov 6, 2024
Messages
4
Likes
5
Look up the concept of an efuse, it’s how modern consoles attempt to prevent being cracked. Essentially you have a very thin trace inside an IC and you run a considerable amount of current through the trace until electromigration does its work and causes the trace to break and go open
 
Top